1) British condiment 2) Mayonnaise-like dressing 3) Salad dressing 
Salad cream is a creamy yellow condiment based on an emulsion of about 25-50 percent of oil in water, emulsified by egg yolk and acidified by spirit vinegar. It may include other ingredients such as sugar, mustard, salt, thickener, spices, flavouring and colouring. It was introduced in the United Kingdom in the 1920s, where it is used as a salad d...
[n] - (British) a creamy salad dressing resembling mayonaise
noun a creamy salad dressing resembling mayonnaise